Process for the refining of sperm oil or wax



Patented Apr. 20, 1937 I PROCESS FOR THE REFINING F SPERM OIL OB WAXWilhelm Holwech, Oslo, Norway No Drawing. Application February 4, 1935.I Serial No. 4,993

2 Claims.

This invention relates to marine oil products of the type containing ahigh percentage of esters of wax alcohols and has for its object aprocess of improving the quality of this type of 5 material.

It is known that a group of animal oils obtained from denticete whales,delphines and certain classes of shark contain a high percentage ofunsaponiflable matter substantially consisting of monovalent alcohols ofhigh molecular weight, present in the oil in the form of fatty acidesters. These esters possess the character of solid and liquid waxes.

In adition to esters of wax alcohols the com- 1 mercial oils of thistype frequently also contain a percentage of glyceride fats. In most ofthe uses to which the oils are put, this percentage of glycerides ishowever undesirable and is considered as a harmful impurity. As aconsequence of this the commercial value of the oils decreases withincreasing percentage of glycerides and it therefore represents aproblem of considerable industrial importance to separate the glyceridesfrom the esters of the wax alcohols.

The solution of this problem, however, is connected with greatdifliculties, and as far as I am aware of the various attempts hithertomade to solve this problem have not met with success. I To remove theglycerides by means of saponifl- 30 cation is not possible because theesters of the wax alcohols are saponifled simultaneously with theglycerides. Attempts to effect separation by means of fat-decomposingferment have also not led to practically useful results.

The present invention now has for its object a process by means of whicha sufficiently complete separation of the glycerides from the saidesters of alcohols other than glycerol is obtainable. This invention isbased on the surprising dis- 40 covery that the esters of the waxalcohols contained in the said 011 are capable of being distilled ofl.from the glycerides without being decomposed to any appreciable degree.

An important feature of the present process 45 therefore consists insubjecting the products in question to a distillation treatment. The useof distillation under reduced pressure to separate free fatty acids fromglycerol esters is well known. And it is also well known to refine fattyacids by 50 means of such distillation. The fatty acids are known to bevolatile in vacuum at temperatures from about 150 C. to about 280 C.,but the esters have been considered as nonvolatile. Thus according to'the present knowledge the glycerol 55 esters of fatty acids havingmolecular weights above that of myristic acid cannot be distilledwithout decomposition even by the use of the highest vacuum attainableby modem means.

Contrary to the generally recognized conceptions regarding the stabilityof fatty acid esters of high molecular weight at high temperatures ithas now been ascertained that the wax-like esters of the marine oils inquestion are capable of being separated from the glycerol esters bydistillation.

The process according to the invention is applicable to the oils as wellas to products of semiliquid or solid consistency obtained from the oilsand in general to any product containing mixtures of fatty acidglycerides and wax-like esters of the type contained in sperm oil.

The temperatures and pressures employed in the distillation will have tobe varied between wide limits according to the character of the oil aswell as to the purpose for which the products are to be employed.Products sensible to heat should be distilled at comparatively lowpressures, while less sensible oils or waxes may be subjected tocomparatively high distillation temperatures. By means of fractionaldistillation the various constituents of the distillable matter may berecovered separately.

The completeness of the separation of glycerides from other esters willvary with the character of the material and the conditions of operation.The same remark applies also as regards the percentage of the waxyesters present which are distilled off from the treated material. As anexample may be mentioned that in one of the experiments made thedistillate obtained from a sperm oil containing about 15 percent ofglycerol esters and about 85 percent of waxlike esters, about 85 percentof the total quantity of waxlike esters were distilled over atemperature of up to about 340 C.

The composition of the distillation residuum will vary with thedistillation temperature and other conditions and will comprise varyingpercentages of waxlike esters, glycerol esters and decompositionproducts. Usually it will be practically free from acids.

When sufliciently high temperatures have been employed the distillatewill contain the solid as well as the liquid waxlike esters of the rawmaterial. The surprising observation is made that the percentage of freefatty acids in the distillate is low and usually only slightly higherthan in the raw material, in spite of the fact that very highdistillation temperatures are made use of. In some of the experimentsmade it has been found that the percentage of free fatty acids increasedfrom about 0,25 per cent to about 1,55 per cent.

During the distillation operation indifferent gases or steam in asuperheated or moist condition or any other vapour for example vaporizedorganic substances may be passed through the distillation chamber whendesired.

It may also sometimes be suitable to make use of the method known fromthe fatty acid industry, consisting in mixing the original oil withother substances having a lower boiling temperature, for example;benzene, benzine, petroleum, alcohols and the like and to subject themixture to the distillation treatment. The added volatile substanceswill evaporate and will bring about a decrease of the partial pressureof the waxlike esters in the vapour, so that the distillation may takeplace at a correspondingly lower temperature. It is possible to so electthe volatile substances added that they are capable of being readilyseparated from the distilled esters by fractional condensation or otherfractionating treatment.

The distillation operation may be carried out as a simple vacuumdistillation in batch operation or it may be carried into effect as afrac tional distillation in continuously operated apparatus.

EXAMPLE I Vacuum distillation in batch operation Sperm oil containing0,25 per cent free fatty acids, about 15 per cent glyceride fat andabout 85 per cent wax-like esters was heated in the distillationapparatus, an inert gas (nitrogen) being blown into the oil. During thedistillation the pressure was maintained at about 5-10 mm. Hg. Thefollowing fractions were obtained:

Percent of the oil Fraction 1. 20 to 305 C 14 Fraction 2. 305 to 325 C43 Fraction 3. 325 to 340 C 14 Distillation residuum 28 Fraction 1,contains free fatty acids originated from the original oil. In Fraction2, only very little free fatty acids are contained, while Fraction 3,again contains free fatty acids derived from a beginning decomposition.

The distillation residuum is practically free from acids. All of thefractions are capable of being freed from free fatty acids by means 01'a treatment with alkali or by means of a fractional distillation.

EXAMPLE II Continuous distillation in column apparatus A marine oilcontaining wax-like esters is heated in a system of pipes to the desiredtemperature (for example 340 0.). The heated oil is passed into a columnapparatus of the usual type employed in the vacuum distillation of fattyacids. Temperature of feed and amount of reflux is controlled in suchway that about 20-30% of the oil containing the main part of the notdistillable glyceride fat is taken out at the bottom of the column.

The vapours from this first stage of the process are passed into anothersection of the same or into another column and are subjected tofractional condensation. 65 to 75 per cent of the 011 containing themain quantity of wax-like esters are present in the vapours and may becondensed.

The temperature in the upper part of this column can be maintained atsuch height that the main quantity of the free fatty acids is stillpresent in the form of vapour. This temperature will vary with thepressure employed and the character of the fatty acids present and mayfor example be presumed to be about 180C. to 280 C. The vapour from thisstage is passed to the condensation apparatus and to the pump by meansof which the required vacuum is maintained.

EXAMPLE III Sperm oil is subjected to the treatment usually employed toseparate spermwax from the oil. The crude wax is subjected todistillation according to Examples I or H. The remaining oil isseparately distilled according to Examples I or II. The residuum fromthe distillation of the wax is mixed with the residuum from the oildistillation and is employed as a raw material in the manufacture ofsoap.

EXAMPLE IV Distilled wax-like esters obtained according to Examples I,II, or III are cooled to effect crystallization of the solid fraction ofthe material. The solids are removed by pressing and both fractionsfreed from fatty acids. The resulting products are suitable for everyuse in which a sperm oil or a sperm wax of high grade quality isrequired.

EXAMPLE V Distilled wax-like esters obtained according to Examples I,II, or III are subjected to a hardening treatment by means of hydrogenin the presence of a catalyst.

The hardening may be arranged as a treatment of the liquid fractionfreed from the solid fraction by cooling and pressing.

The resulting wax is suitable for every use in which a wax of high gradequality is required.

It will be understood that the invention is not limited to the variousdetails of operation mentioned in the above examples and that the rawmaterials employed as well as the conditions of operation may be variedwithin wide limits.

The products obtained by the distillation treatment aresuitable fordirect use in the various field in which sperm oil and wax is commonlyemployed, such as for example as lubricants,

candles, dressing means, soap manufactures,

cosmetics, ointments etc.

The products may also be subjected to further refining treatments and asa raw material in various industries in which the products aredecomposed or converted into chemical products for uses other than thoseof crude or refined oils or waxes.

It is possible by cold clarifying and pressing of the distillates toseparate out liquid wax-like esters solidifying at low temperatures.Such'cold clarifying products which are practically free from glyceridefats possess excellent properties as a lubricant for machinery andinstruments. They may be used as such or in mixtures with mineral oils.In the last named instance, that is to say, in the manufacture ofsocalled compounded oils the advantage is attained that an increase ofcompounding agents does not involve an increase of the percentage ofglyceride fat. It is a known fact that compounded oils are of limitedusefulness because in many instances the glyceride fat is a. harmfulconstituent. The cold-clarifying products are of great advantage as aconstituent of drilling oils, textile oils, cosmetic preparations andgenerally for all l lytical hydrogenation processes.

purposes in which cold-clarified sperm oils have hitherto been used.

From the press residuum after separation of the liquid fraction waxesters of high melting 5 points may be produced.

These wax-like products are suitable for use in all of the fields inwhich sperm wax has hitherto been used. These products are particularlyadvantageous because they are free from glyceride fat.

As will be understood from the above, various products obtained by thevacuum distillation according to the present invention are capable ofbeing converted into valuable products by cata- The advantage of suchfurther treatment will be apparent from the following.

From marine oils or oil products of the type containing wax-like estersit is possible by fractional distillation to obtain distillatespractically free from glyceride fat (less than 1 per cent).

It may be mentioned that in a particular example distillation productscontaining 402%- 46,4%-48,4%-51,3% unsaponifiable alcohols,

62,8%57,4%-56,5%-52,3% saponiflable fatty acids, having iodine numbersof '76,0--83,7- 85,0100,0 and being practicallyfree from glyceride fatshave been obtained by fractional distillation of a sperm oil containingl4,5% glyceride fat, 32.4% unsaponifiable alcohols, 65,9% saponifiablefatty acids andhaving an iodine number of 86.

By catalytic hydrogenation of the products, wax-like esters having highmelting points and low iodine numbers may be obtained and which incomposition are very much like the best known qualities of refined spermwax qualities.

These last named types of wax according to the literature have acomposition as follows:

41 %-54,3% unsaponiflable alcohols, 49-53,5% saponifiable fatty acids,iodine numbers 3-8 and glyceride fats up to about '7 The hardeneddistillation products according to the present invention will thus be ofa quality superior to refined sperm waxes because they do not containglyceride fat.

By direct hydrogenation of undistilled sperm oil, products are obtainedwhich contain 30-40 per cent unsaponiflable alcohols, 60-68 per cent 0saponiflable fatty acids and 10 to 18 per cent of glyce ride fat.

Even by the most extensive hydrogenation of undistilled sperm oil it isnot possible to produce products of a composition corresponding to that55 of sperm wax of ordinary quality. The difference in composition,particularly the percentage of glyceride fat, will have a harmfulinfluence on the quality.

The hydrogenation treatment may be applied 60 to each individualfraction of the distillate and also to the distillation residuum. Thelwdrogenation may be carried out as a separate operation, in which thevarious fractions (or the residuum respectively) are treated. It 'may,however, also be carried out as steps of the distillation itself or inimmediate conjunction therewith. The distlllates are capable of beinghydrogenated in liquid conditions as well as in the form of vapours.

In certain cases it is found to be of advantage to elect hydrogen as.the gas which is blown into the still to facilitate distillation.Hydrogen has a low molecular weight and will therefore increase the rateof diffusion of the ester vapours. The use of hydrogen will be ofspecial importance in case the distillation is carried out incombination with a hydrogenation treatment.

In the case of the hydrogenation being carried out in combination withthe distillation and while the distillates are still in the form ofvapours the hydrogen pressure will have to be lower than atmosphericpressure. In the case of the distillates being hydrogenated in a liquidcondition the hydrogen pressure may be raised above atmosphericpressure, the known methods of high pressure hydrogenation ofunsaturated organic substances being then applicable.

This high pressure hydrogenation may also be applied to the distillationresiduum which consists of a mixture of glycerol esters andunsaponiflable matter. In one of my experiments the obtained residuumcontained 10 per cent of unsaponifiable alcohols and 85 per cent ofsaponifiable fatty acids.

By hydrogenation at high pressures according to known methods ofprocedure the fatty acids in the residuum are converted into alcohols ofcorresponding molecular weights (thus raising the' contents of alcoholsfrom. 10 per cent-in the example menti0ned-to a percentage which makesthe manufacture of pure wax alcohols possible).

I claim:

1. Process for the refining of such materials of the sperm 011 type,which contain in addition to the natural wax-like esters also a notableamount of glycerol fat comprising the step of subjecting the material todistillation under reduced pressure at temperatures sufficiently high toeffect evaporation of the natural wax-like esters in an unsplitcondition leaving the glycerol fat as a residuum.

2. Process according to claim 1 in which the distillation is effected attemperatures up tov about 340 C. at pressures at about 5-10 mm. Hg.

WILHEIM HOLWECH.

